Whakaraupō, Te Waipapa Diamond Harbour and Bays wastewater discharge event
Final update 18 February 2026
Environment Canterbury is investigating a wastewater discharge into Te Waipapa Diamond Harbour from a damaged Christchurch City Council (CCC) sewerage pipe on Saturday 7 February that led to a health alert at four bays and rāhui for the Whakaraupō Lyttelton Harbour area.
Important health and rāhui information
The National Public Health Service (NPHS) health warning for Te Waipapa Diamond Harbour, Purau Bay, Kaioruru Church Bay and Te Wharau Charteris Bay, issued on 7 February, was lifted on 12 February as faecal bacteria levels at the sites are now below guideline values. People should continue to check Land, Air, Water Aotearoa (LAWA) - Can I Swim Here? for the latest information on water quality at recreational swimming sites in Waitaha Canterbury.
Te Hapū o Ngāti Wheke (Rāpaki) through the Rāpaki Tangata Tiaki, installed (as of 1700 hours on Saturday 7 February) a seven (7)-day rāhui on the taking of Kai Moana within Whakaraupō. This rāhui has now been lifted.
Wastewater incident details
Our incident team was on site on Saturday (7 February) after being notified of the event by a member of the public. We assisted with the immediate response and assessing environmental impacts of the discharge. A visible contamination plume was observed in the harbour earlier Saturday but moved toward the heads with the outgoing tide.
CCC advised that the discharge was caused by a burst drinking water main that impacted a neighbouring wastewater pipe.
CCC repaired both the drinking water main and wastewater pipe on Saturday afternoon.
Sampling information
Our science team collected samples from each of the swimming sites in Whakaraupō on Sunday (8/2), Monday (9/2) and Tuesday (10/2) to understand if there was any residual microbiological contamination because of the sewage spill in Diamond Harbour on Saturday. We shared these results with NPHS, CCC and rūnaka, which helped inform the health alert status.
The Christchurch City Council also undertook sampling on Saturday (7/2) and Sunday (8/2).
Our role and next steps
As the environmental regulator, we're investigating the sewage discharge. Meanwhile, our ongoing contact recreational water quality monitoring programme will continue through summer, and people should check Land, Air, Water Aotearoa (LAWA) - Can I Swim Here? to see if it's safe to swim.